Principle of Least Privilege
Grant a component only the minimum access it actually needs to do its job — nothing more, so a compromise stays small.
The principle of least privilege says every user, service, and process should hold only the permissions it strictly needs, for only as long as it needs them. It doesn’t prevent a compromise, but it caps the blast radius: an attacker who takes over a service that can only read one table does far less damage than one who takes over a service running with admin rights it never actually used.